power drained by the beagleboard?

Hello.

Can we measure power supplied into the beagleboard (or at least into the OMAP chip) by reading some registers?

I am not able to find any such thing in either the TPS65950 or OMAP3530 documentations.

Thanks,
Gabi Voiculescu
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One way is to read the A/D registers on the TPS65950 and do a calculation. This is covered in the System Refeence Manual. But, it is not precise reading as it does move around a lot based on the instructions and other system activity. It will give you a ball park reading on the value. The best method is an external current meter.

Gerald

One way is to read the A/D registers on the TPS65950 and do a calculation. This is covered in the System Refeence Manual. But, it is not precise reading as it does move around a lot based on the instructions and other system activity. It will give you a ball park reading on the value. The best method is an external current meter.

Why not take several samples and average to get a more stable result. For example, sum 4 samples and right shift the result by 2, or sum 8 samples and right shift the result by 3. The more samples you use, the more stable the result.

Gerald

Well, as a matter of fact, that is what I do in the production test SW. It really depends on how “precise” you need it to be. In most cases I think it is really used as a relative reading, where you see if the current went up or down based on what actions you have taken in SW, such as lowering the speed or turning off the DVI framer for example. The read point is take att he main DC input, so it is a reading of the entire board and not the OMAP only.

Gerald

I have trouble finding this “System Reference Manual”.

Is it a Omap3530 or a tps65950 document?

I have “TPS65950 - Integrated Power Management/Audio Codec - Data Manual” and it does not cover the ADC registers.

I also have “BeagleBoard System Reference Manual” but my hw is Beagleboard Rev C3.

Thanks,
Gabi Voiculescu

The latest System Reference Manual link is on the beagleboard.org website main page. http://beagleboard.org/static/BBSRM_latest.pdf

The latest version is for the C3 board. The ADC are not covered in the TPS65950 Data Manual. You need the Techincal Reference Manual. http://beagleboard.org/static/BBSRM_latest.pdf

Gerald

Thank you.

To fix an edit problem the

TPS65950 OMAP Power Management and
System Companion Device
Silicon Revision 1.0
Version D
Technical Reference Manual

can be found here: http://focus.ti.com/lit/ug/swcu050d/swcu050d.pdf

Hi,
   I need to measure power of beagleboard. Can anyone help me to write
a test app for this .

Thanks in advance
Tapas